13-229
To:       J3
From:     Malcolm Cohen
Subject:  Interp on initialization and PARAMETERs
Date:     2013/01/29

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NUMBER: F08/0090
TITLE: 	What restrictions apply to initialization and PARAMETER?
KEYWORDS: PARAMETER, initialization, conformable, type conversion
DEFECT TYPE: Clarification or Erratum
STATUS: J3 consideration in progress

QUESTION:

Consider the programs

  Program m200c3_1
    Integer :: a(10,10)
    Parameter (a = [ (i,i=1,100) ] )
    Print *,a
  End Program

  Program m200c3_2
    Parameter (b = 'ok')
    Print *,b
  End Program

  Program m200c3_3
    Integer :: x(23) = [ 1 ]
    Print *,x
  End Program

  Program m200c3_4
    Integer :: y = 'ok'
    Print *,y
  End Program

The PARAMETER statement for the named constant A has an expression
whose shape does not conform with that of A.  The PARAMETER statement
for the named constant B has an expression whose type does not conform
to that of B.  The <initialization> for X is not conformable in shape.
The <initialization> for Y is not conformable in type.

There appears to be no requirement either for shape or type
conformance, in Fortran 2008 or in previous Fortran standards, except
for initializing data pointers.

Q1. Do any of these programs conform to Fortran 2008?

Q2. If there is meant to be a requirement for the shapes to conform or
    for the types to be convertible, should this not be a constraint?

ANSWER:

A1. No, these programs do not conform to Fortran 2008, as no
    interpretation is established for any of them.  Edits are
    provided to clarify this.

A2. This is not a constraint.  A future revision of Fortran might
    choose to mandate diagnosis of these errors.

EDIT to 10-007r1:

[88:30+] 5.2.1 Syntax, Insert new paragraph at end of subclause
  "If <initialization> appears for a nonpointer entity,
   - its type and type parameters shall conform as specified for
     intrinsic assignment (7.2.1.2);
   - if the entity has implied shape, the rank of <initialization>
     shall be the same as the rank of the entity;
   - if the entity does not have implied shape, <initialization> shall
     either be scalar or have the same shape as the entity.".

[107:12+] 5.4.11 PARAMETER statement, after p2, Insert new paragraph
  "The constant expression that corresponds to a named constant shall
   have type and type parameters that conform with the named constant
   as specified for intrinsic assignment (7.2.1.2).  If the named
   constant has implied shape, the expression shall have the same rank
   as the named constant; otherwise, the expression shall either be
   scalar or have the same rank as the named constant.".

SUBMITTED BY: Malcolm Cohen

HISTORY: 13-nnn  m200  Submitted by Malcolm Cohen.

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